Wiper blade for cleaning panes, especially for cleaning the panes of a motor vehicles

ABSTRACT

A wiper blade for cleaning windows, especially of motor vehicles, is proposed, which has an elongated, rubber-elastic wiper strip ( 20 ) that can be pressed against the window ( 22 ) and is retained by a multi-member support bracket system ( 12 ) that has a main bracket ( 14 ), located in the middle portion of the support bracket system, is provided with a bolt ( 26 ), oriented transversely to the length of the wiper blade ( 10 ), for pivotable connection to a wiper arm ( 28 ) that is urged toward the window and is driven to swing, resulting in one wiper blade half near the swing axis and one wiper blade half remote from the swing axis, and the wiper blade is provided with spring means, which under tension, when the wiper blade is pressed against the window, additionally urge the half remote from the swing axis toward the window. A favorable embodiment and disposition of the spring means in terms of the masses to be moved is achieved by providing that the spring means are embodied as a leg spring ( 60 ), of which one leg ( 64 ) is braced directly or indirectly on the pivot bolt ( 26 ) and its other leg ( 66 ) is fixed to the half near the swing axis of the main bracket ( 14 ).

PRIOR ART

[0001] The invention is based on a wiper blade as generically defined bythe preamble to claim 1. In a known wiper blade of this type, the springmeans are formed by a tension spring, suspended by one end from the mainbracket, with its other end retained on the outermost claw bracket,remote from the swing axis, that holds the wiper strip. The tensionspring is positioned and designed such that particularly when sweepingover the vehicle windows that are most markedly curved spherically inthe peripheral or corner regions, the end remote from the swing axis ofthe wiper strip is pulled outward toward the window, via the contactpressure originating in the wiper arm, and is thus additionally urgedtoward the window. The goal is that thereby, these regions of thewindshield that count as problem zones can be properly cleaned as well.A disadvantage, however, is the relatively long and hence heavy tensionspring, which considerably increases the weight of the wiper blade,which has to be braked at the turning points of the swing and thenspeeded up again out of them. Also in this connection, the dispositionof the tension spring in the region of the wiper blade remote from theswing axis is a disadvantage.

ADVANTAGES OF THE INVENTION

[0002] In the wiper blade of the invention with the definitivecharacteristics of the body of claim 1, the leg spring is extremelycompact and comparatively light in weight, so that the loads acting onthe drive system of the wiper system during wiper operation are reducedmarkedly. Its disposition in the region of the pivot bolt contributes tothis as well, because it shifts the center of gravity of the wiper bladetoward the swing axis.

[0003] If the main bracket has two cheeks spaced apart from one another,on which the ends of the pivot bolt are retained, and a connectionadapter adapted to the free end of the wiper arm is supported in a waycapable of swinging between the cheeks on the pivot bolt, with one legplunging into a recess in the adapter and the other leg being fixed toone of the two cheeks, then the leg spring is essentially positioned ina space existing between the cheeks, defined by the wiper arm engagingthe adapter, and hence is practically invisible.

[0004] An operationally reliable bracing of the prestressed leg springis assured if the body of the leg spring is located in a throat of theconnection adapter that extends parallel to the pivot bolt between thetwo cheeks.

[0005] Expediently, the other leg of the leg spring engages one cheekfrom beneath with an extension, so that given a suitably prestressed legspring, the wiper blade half remote from the swing axis is urged towardthe window.

[0006] Reliable securing of the leg spring in its operating position isachieved by fixing the extension of the other spring leg in a recess ofthe cheek of the main bracket.

[0007] Further advantageous refinements and features of the inventionare recited in the ensuing description of an exemplary embodiment shownin the associated drawing.

DRAWING

[0008] Shown in the drawing are: FIG. 1, a plan view on a wiper blade ofthe invention with the associated wiper arm; FIG. 2, an enlargedfragmentary side view of the wiper blade of FIG. 1 in the direction ofthe arrow II; FIG. 3, a fragmentary section through the main bracket ofthe wiper blade along the line III-III of FIG. 1, in an enlarged viewwhose location can be seen from FIG. 5; FIG. 4, the section faces of across section through the main bracket of FIG. 3 taken along the lineIV-IV, with the end of the other leg of a leg spring drawn in; FIG. 5,the section face of a cross section through the main bracket of FIG. 3taken along the line V-V, with the location, represented by the lineIII-III, of the section III-III of FIG. 3; and FIG. 6, a perspectiveview, not to scale, of a connection adapter, belonging to the wiperblade, for connecting the wiper blade to the wiper arm.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0009] A wiper blade 10 shown in FIGS. 1 and 2 has a support bracketsystem 12, known per se, which is constructed from a plurality ofsupport brackets connected pivotably connected to one another. Hence ithas a primary main bracket 14, to whose ends secondary claw brackets 16are pivotably connected. The main bracket 14 is thus located in themiddle portion of the support bracket system. The claw brackets 16, withclaws 18, engage an elongated, rubber-elastic wiper strip 20, which ispressed with its wiper lip against the surface of a windshield 22 of amotor vehicle that is to be wiped. The main bracket 14 has twospaced-apart lateral cheeks 24, on each of which one end of a pivot bolt26 is retained. The pivot bolt is disposed in the middle portion of themain bracket 14 and extends transversely to the length of the wiperblade 10, that is, of the main bracket. The pivot bolt 26 serves thepurpose of pivotable connection of the wiper blade 10 to a wiper arm 28that is urged toward the window 22 and is driven to swing about a swingaxis 34 in the direction of the double arrow 35. The swing axis islocated on the end of the wiper arm that is remote from the wiper blade,that is, from the pivot bolt 26. Arrangements of this kind are wellknown to one skilled in the art, for instance from Published,Nonexamined German Patent Application DE-OS 15 05 257. As FIG. 1 shows,the wiper blade 10 pivotably connected to the wiper arm 28 thus has oneend 30 near the swing axis and one end 32 remote from the swing axis.

[0010] As can be seen from FIG. 3, the free end, remote from the swingaxis 34, of the wiper arm 28 is curved in hooklike fashion (FIG. 2). Itthus changes over to a first hook leg 36, which is adjoined by a curvedportion 38, which in turn merges with a second hook leg 40. These wiperarm hooks 36, 38, 40 form the wiper arm part of a connecting device withthe aid of which the wiper blade 10 can be pivotably connected to thewiper arm 28. The wiper blade part of this connecting device includesthe aforementioned pivot bolt 26, onto which a connection adapter 42 issnapped. The adapter 42, made from an elastic plastic, is shown inperspective in FIG. 6. It has a blocklike body 44, with a bearing bore46 that is adapted to the diameter of the pivot bolt 26. The bearingbore itself is open at the edge, toward the underside 50 of the body 44,via an introduction channel 48. The width 42 of the adapter is adaptedto the spacing 54 (FIG. 4) between the two cheeks 24 of the main bracket14 in such a way that it can be positioned between these cheeks as muchas possible without play. To that end, the adapter 42 is placed with itsintroduction channel 48 on the pivot bolt 26 and snapped into thebearing bore, in the course of which the introduction channel 48converging toward the bearing bore 46 is widened elastically. Theadaptation between the diameter of the pivot bolt 26 and the bearingbore 46 is made such that the connection adapter 42 can swing as much aspossible without play about the longitudinal axis of the pivot bolt. Onits top 56, the plastic adapter 42 is provided with a detent tooth 58(FIG. 6), which snaps into an associated recess of the wiper arm whenthe wiper blade 10 is pivotably connected, in the manner shown in FIG.3, to the wiper arm 28. In the process, the two hook legs 36 and 40 reston the top 56 and underside 50, respectively, of the adapter, and thehook leg 36 thus prevents opening of the introduction channel 48 andhence unintended detachment of the wiper blade 10 from the wiper arm 28.The detent tooth 58, in cooperation with the recess associated with itin the wiper arm 28, prevents a relative displacement between the wiperarm 28 and the wiper blade 10. From FIGS. 3 and 5, it can be seen that aleg spring 60 is disposed on the side of the adapter 42 toward the swingaxis 34. This leg spring has a spring body 62 in the manner of a helicalcompression spring, which has a plurality of windings. Each terminalwinding merges with a respective spring leg 64 and 66, which each extendessentially at a tangent from a terminal winding away from the springbody 62. By means of a targeted tensing motion of the spring legs 64,66, in the course of which at least one of the two legs is pivoted aboutthe longitudinal axis of the spring body 62, this leg spring, which canalso be called a torsion spring, can be prestressed. Under thisprestressing, the one, relatively short spring leg 64 is introduced intoa bore 68 in the adapter 42, while the other, longer spring leg 66, withan extension 70 (FIG. 4) disposed on its free end, engages one cheek 24of the main bracket 14 from beneath. What is essential here is that theextension 70 engages a shoulder of the cheek 24 that is oriented towardthe window 22 from beneath. This shoulder could also be formed by partof the wall of a bore disposed in the cheek, which bore is engaged onthe inside by the spring leg 66 with its extension 70. The engagementpoint of the spring leg 66 or of the extension 70 on the cheek 24 islocated—in terms of the pivot bolt 26, on the side of the main bracket14 toward the end 30 of the wiper blade that is near the swing axis. Forsecure bracing of the leg spring on the connection adapter 42, thespring body 62 is braced over its entire length in a throat 72 of theadapter, which throat extends parallel to the pivot bolt 26, that is,parallel to the bearing bore 46, over the full width 52 of the adapterbetween the cheeks 24. To achieve a fixation of the leg spring 60 in itsoperating position, shown in FIG. 3, the extension 70 of the spring leg66 rests in a recess 74, open at the edge, on the underside of the cheek24. The prestressing of the leg spring is selected such that the springleg 66, with its extension 70, urges the main bracket 14 in thedirection of the arrow 76 (FIG. 3), so that the wiper blade 10 seeks torotate about the pivot axis of the bearing bolt 26 in the direction ofthe arrow 78. It is clear that in the process, beyond the contactpressure (arrow 77) originating in the wiper arm 28, the half of thewiper blade remote from the swing axis, and in particular the end 32remote from the swing axis, is subjected to a stronger contact pressureagainst the window 22 than the half near the swing axis or the end 30near the swing axis of the wiper blade 10.

[0011] The wiper blade 10 of the invention is accordingly provided withspring means which are embodied as a leg spring 60. One spring leg 60 isthus braced indirectly—since it dips into the recess 68—via the adapteron the pivot bolt 26, while the other leg 66 is fixed to the half of themain bracket 14 near the swing axis.

[0012] It is thus possible in a simple way—for instance by varying theprestressing of the leg spring—to adapt the additional loading of thewiper blade half remote from the swing axis to the applicablerequirements, which depend on the type of vehicle involved.

1. A wiper blade (10) for cleaning windows (22), especially of motorvehicles, having an elongated, rubber-elastic wiper strip (20), whichcan be pressed against the window and which is held by a multi-membersupport bracket system (12) that has a main bracket (14), and the mainbracket, located in the middle portion of the support bracket system, isprovided with a bolt (26), oriented transversely to the length of thewiper blade, for pivotable connection to a wiper arm (28) that is drivento swing and is urged toward the window, resulting in one wiper bladehalf near the swing axis and one wiper blade half remote from the swingaxis, and the wiper blade is provided with spring means, which whenunder tension, with the wiper blade pressed against the window,additionally urge its half remote from the swing axis toward the window,characterized in that the spring means are embodied as a leg spring(60), one leg (64) of which is braced directly or indirectly on thepivot bolt (26) and the other leg (66) of which is fixed to the half ofthe main bracket (14) near the swing axis.
 2. The wiper blade of claim1, characterized in that the main bracket (14) has two spaced-apartcheeks (24), on which the ends of the pivot bolt (26) are retained, andbetween the cheeks on the pivot bolt, a connection adapter adapted tothe free end of the wiper arm (28) is supported in a way capable ofswinging, with one leg (64) plunging into a recess (68) in the adapter(42) and the other leg (66) being fixed to one of the two cheeks (24).3. The wiper blade of claim 2, characterized in that the body (62) ofthe leg spring (60) rests in a throat (72) of the connection adapter(42), which throat extends parallel to the pivot bolt (26) between thetwo cheeks (24).
 4. The wiper blade of one of claims 2 or 3,characterized in that the other leg (66) of the leg spring (60) engagesa cheek (24) from beneath with an extension (70).
 5. The wiper blade ofclaim 4, characterized in that the extension (70) of the other springleg (66) is fixed in a recess (74) of the cheek (24).